The present invention relates to a sorbent (substance that sorbs) comprising spherical particles of activated carbon formed from a pitch and/or a synthetic, organic high polymer, to which a non-crystalline compound of zirconium has been deposited. More in detail, the present invention relates to a sorbent comprising spherical particles of activated carbon formed from a pitch and/or a synthetic, organic high polymer, to which a non-crystalline compound of zirconium has been deposited in an amount of 1 to 10% by weight (calculated as ZrO.sub.2) of the amount of the sorbent and a process for preparing the sorbent comprising the steps of impregnating the spherical particles of activated carbon with an aqueous solution of a water-soluble compound of zirconium, treating the thus impregnated spherical particles of activated carbon with an alkali and thermally treating the thus treated spherical particles of activated carbon at a temperature of 400.degree. to 1000.degree. C. to obtain the sorbent comprising the spherical particles of activated carbon depositing a non-crystalline compound of zirconium in an amount of 1 to 10% by weight (calculated as ZrO.sub.2) of the weight of the sorbent.
Within the living body of the patients having their hepatic- or renal functions impaired, decomposition of the poisonous substances within their body and excretion thereof from their body are hardly carried out, and accordingly, such poisonous substances (hereinafter referred to as toxins) accumulate within their body resulting in causing various physiological disturbances to the patient. Since the number of the patients having their hepatic- or renal functions impaired is in a tendency of increasing yearly, the development of the substitutive machinery and tools for excreting the toxins to outside of the patient's body in place of the impaired viscera, i.e., artificial viscera, has been eagerly desired.
At present, as the artificial viscera acting as a substitutive kidney, artificial kidney of removing hemo-toxins by blood dialysis has been most popularized. However, according to the demerits of such a type of artificial kidney of taking a long time for blood dialysis and of the heaviness of the apparatus for dialysis, the most popularized type of artificial kidney is not necessarily a satisfiable artificial kidney.
Under such conditions, the development of the type of artificial kidney utilizing adsorptive function of activated carbon has been promoted and studies for reducing the time of dialysis and for miniaturizing of the apparatus for dialysis have been promoted with the object of solving the demerits of the present type of artificial kidney.
Hitherto, it has been well known that the patients suffering from chronic renal failure show symptoms of hyperphosphatemia due to disturbance of phosphate excretion. Although it is possible to remove phosphate from the blood to an extent by blood dialysis, it is hardly possible to prevent the complication of hyperphosphatemia in the patient of chronic renal failure.
On the other hand, activated carbon utilized carefully in the artificial viscera scarcely causes disturbances on the patient to whom such an artificial viscera is applied, and it is excellent in removing organic metabolites such as creatinine, etc. from the blood. However, the activity of activated carbon in removing inorganic substances such as phosphate, etc. from the blood is extremely low, and accordingly, the effect of activated carbon in reducing the concentration of phosphate within the blood has not been expected. Consequently, the development of a sorbent having a capability of removing phosphates in the blood while retaining the capability of activated carbon of removing organic metabolites in the blood has been strongly desired.